Feline relapsing polychondritis: two cases and a review of the literature

Only 11 reports of cats with relapsing polychondritis (RPC) were found in the literature. We describe two additional cases and provide a review of the literature. Predominantly young to middle aged cats are affected (range 1.5 to 14.5 years, median 3 years). There is no sex predilection for feline RPC. In all cats with feline RPC, the ears were affected. The findings in one of our cases and one case in the literature raise the question if other organs such as the joints, the eyes or the heart may be involved in feline RPC. The histological lesions observed in biopsy samples of the ears were similar in all cats. Glucocorticoids were not effective in the treatment of RPC. Dapsone appeared to result in some clinical improvement but side effects were observed in one of four cats. Some cats improved without treatment.